1. Field of the Invention
The present invention relates to an electrical connector for `S`-terminal on a video equipment which is constructed in such a way that a brightness signal and a color signal is separately derived as reproduced outputs in order to realize a higher quality image.
2. Description of the Prior Art
Recently, in order to realize a higher quality image on a display both of the conventional VHS and BETA systems have been substituted by SUPER VHS (abbreviated as `S-VHS`) and ED BETA systems, respectively. As is well known, these new systems have excellent characteristics in that they are capable of preventing the reduction of an FM brightness signal superimposed on a color signal and of slightly widening a band-width of the color signal. More specifically, they are capable of separately deriving the brightness signal `Y` and the color signal `C` as the reproduced signals.
Thus the video equipment of this kind has a `Y/C` separate input/output terminal, commonly referred to as an `S`-terminal, through which the video equipment is connected to a television set and a video camera. For this purpose, an electrical connector for an `S`-terminal has been developed and widely utilized. More specifically, the prior art connector of this kind is constructed and connected to cables in the manner as described below.
The prior art arrangement of the electrical connector will briefly be described below with reference of FIGS. 6, 7 and 8. A cable 41 comprises a coaxial line 44 consisting of a core wire 42 and an outer sheath wire 43, as well as another coaxial line 47 consisting of a core wire 45 and an outer sheath wire 46. Each of said core wires 42 and 45 of the two coaxial lines 44 and 47 are crimped to each of core terminals 48 and 49, respectively. The core terminals 48 and 49 are mounted in a holder 50 made of electrical insulation material which is then held in a metal pipe 51. The outer sheath wires 43 and 46 are connected in the manner as stated below. The sheath wire 43 of the coaxial line 44 is covered with a heat shrinkable tube 52 as shown in FIG. 7. Heat is applied to the tube 52 shrinking it to form a bundle of the sheath wire 43. In FIG. 8, a bifurcated portion 53 of the coaxial line is also covered with a heat shrinkable tube 54 and heat is applied to shrink the tube 54, thereby protecting the bifurcated portion 53. The equivalent process applies to the sheath wire 46 of the other coaxial line 47. The sheath wires 43 and 46 are crimped to external wiring terminals 55 and 56 which are then mounted in the holder 50.
The prior art arrangement as stated above has a number of deficiencies. First, it takes a longer time to connect the sheath wires 43 and 46 of the coaxial lines 44 and 47 to the external wiring terminals 55 and 56, respectively. Second, due to the use of additional components such as the heat shrinkable tubes and the like, extra amount of materials is required. Third, the metal pipe 51 is not efficiently utilized because it provides only a mechanical positioning capability.
In view of the above, it is an object of the present invention to provide an electrical connector for an `S`-terminal in which the connection of respective outer sheath wires of two coaxial lines with respective sheath wire terminals can be easily and efficiently be achieved.
It is another object of the present invention to provide an electrical connector for an `S`-terminal in which a metal pipe can effectively be utilized not only as a mechanical member but also as an electrical member, thereby saving the amount of additional materials which would be required.
In order to achieve the above objects, the present invention provides an electrical connector for an `S`-terminal, which is used for making connections between video equipment including a video recording/reproducing apparatus and a television set. This connection is made through a cable 1 having a pair of coaxial lines 4 and 7 each made of a core wire and an outer sheath wire. The electrical connector is provided with a pair of core wire terminals 8 and 9 to which core wires 2 and 5 of the coaxial lines 4 and 7 are respectively mechanically and electrically connected and also with a pair of sheath wire terminals 16 and 17 to which the sheath wires 3 and 6 of the coaxial lines 4 and 7 are electrically connected.
An electrically conductive pipe 11 surrounds the outside of holder 10 made of an electrical insulation material. The pipe positions the pair of core wire terminals 8 and 9 and the pair of sheath wire terminals 16 and 17, and has the sheath wires 3 and 6 of the pair of coaxial lines 4 and 7 jointly connected to the rear end 14 of the conductive pipe 11. The sheath wires 3 and 6 of the pair of coaxial lines 4 and 7 are also, respectively, connected to the pair of sheath wire terminals 16 and 17 via the conductive pipe 11 by the electrical connection of the pair of sheath wire terminals 16 and 17 to the conductive pipe 11.
According to the arrangement as stated above, electrical connection of the cable 1 and the electrical connector is effected as follows. The core wires 2 and 5 of the coaxial lines 4 and 7 are connected to the core wire terminals 8 and 9 in the conventional manner. The sheath wires 3 and 6 of the coaxial lines 4 and 7 are formed into a bundle which is connected to the rear end 14 of the conductive pipe 11. In one embodiment, the bundle of the sheath wires is crimped to the rear end by a crimp terminal 15 mounted thereon. In such a connection, there is no need for the heat shrinkable tube and the like as in the prior art arrangement. At this time, the sheath wire terminals 16 and 17 mounted inthe holder 10 have been electrically connected to the front portion of the conductive pipe 11. More specifically, a resilient member 19 extending from a coupler member 18 of the sheath wire terminals 16 and 17 is in resilient contact with the inner peripheral surface of the conductive pipe 11. Thus, the sheath wires 3 and 6 of the coaxial lines 4 and 7 are electrically connected to the sheath wire terminals 16 and 17 via the conductive pipe 11. According to this arrangement, there is no need for the crimp terminal to be used for connection of sheath wire terminals 16 and 17 to the sheath wires 3 and 6. In addition to positioning the holder 10, the conductive pipe 11 also serves as the electrical connection member.